Valve elements are used to regulate or control the flow of material by opening, closing, or partially obstructing various passageways. One type of valve or valve element is a main valve, which can be used in a number of applications, such as within a hydrant shoe of a dry-barrel fire hydrant. Main valves in hydrants occasionally fail to seal properly or even fail catastrophically as the result of deformation or other degradation of the main valve over time. Deformation and other degradation is typically caused by the mechanical forces that act on the valve during operation including when the valve is closed or being tightened. This deformation is typically caused by the flexibility of the material, such as rubber, used to make the valve or by the material of the outer portion of the valve that comes into contact with the hydrant in cases where the valve has an internal rigid structure formed from a different material. While incorporating an internal rigid structure in a valve can improve the performance and durability of the valve, problems associated with incorporating such structure include the difficulty in centering the structure and holding the structure in place during the manufacturing process, the difficulty in maintaining a consistent shell thickness around the structure, and corrosion of the rigid structure due to exposure to water necessitated by the design of the valve or the process for manufacturing the valve.